FIFFY8, Ludovica Diroma and lenkal welcome to FlyerTalk and a particular welcome to the Ryanair zone. Now that you've joined us and posted I hope you continue to do so. You will find many knowledgeable people here who are willing and able to assist.

Ryanair are clearly pulling a fast one here and should not be misleading customers in this way. The T&Cs are clear and unambiguous and you shouldn't be paying twice (or more) for seats, luggage and other extras when changing flights under their “Zero” Flight Change Fee policy.

Here is the policy and the T&Cs (I'm posting them here in full just in case they remove them in the future) and I have bolded the relevant portions for ease: https://www.ryanair.com/gb/en/useful-info/no-change-fee

“Zero” Flight Change Fee Policy

Change of plan? Don’t worry, we have Zero Change Fees.

We know your plans may change, so we've dropped our flight change fees for all new bookings made before 30 September 2021, for travel before 31 December 2021. You can now make up to two flight changes for travel by 31 December 2021. This gives you complete flexibility and peace of mind.

Our Zero Change Fee promo is applicable for bookings made after 10 June 2020. Flight changes must take place at least 7 days before the original scheduled departure dates to avail of promo. Fare and product price difference may apply.

Terms and Conditions

• “Zero” Flight Change Fee Terms & Conditions are issued by the Ryanair Group, Dublin Office, Airside Business Park, Swords, Ireland (hereinafter ‘Ryanair’).
• The “Zero” Flight Change Fee promo is only applicable to bookings made before 30 September 2021. To avail of the “Zero” Flight Change Fee promo, new flights must travel before 31 December 2021 (incl).
• To avail of the “Zero” Flight Change Fee promo, flight changes must take place at least 7 days before the original scheduled departure dates. Any changes made within 7 days of the original scheduled departure dates will be subject to the standard flight change fee set out in our Table of Fees.
• If the fare associated with new flight dates is more expensive than that paid for the original flight dates, then the customer must pay any difference between the original fare paid and the new fare. Any ancillary product pricing differences must also be paid.
• No change of name is permitted as part of this promotion. All name changes are subject to standard name change fee set out in our Table of Fees.
• Up to two flight date changes with zero flight change fee are permitted to either the outbound, return or both sectors dates or routes in the original booking.
• Further changes (over the 2 free changes above) can be made but will be subject to the flight change fee policy as per article 3.1.5 of our General Terms & Conditions of Carriage, as applicable.  If you have already taken the booked outbound flight, you may still make one change to the return flight date should you so wish.
• If you do not wish to make the flight change for all passengers in the booking, they must contact Ryanair Customer Service Department
• If you have purchased a reserved seat, the same seats will be assigned on the new flight. If the purchased seats are not available, you will be given the option to select new seats. If the new selected seats are more expensive you will be charged the difference.  
• Except as otherwise provided by applicable law, these Terms & Conditions shall be governed by and interpreted in accordance with the laws of Ireland.
• Ryanair’s GTCCs apply.

Do not be distracted or mislead by anything Ryanair tell you on the telephone or in email - they are not entitled to charge you more than once for the products you have already paid for. Before making changes, do a dummy booking for the flights you wish to change to (including all the extras) and take a screenshot of the results. Then go back to your existing reservation and see what ryamair.com quotes you. If there is a difference best to call them and tell them of the issue.

If you have already been overcharged, claim against them using their ADR process.