I upgraded flights booked with Avios from J to F recently, or at least attempted to. I wanted to run through my experience to see if this is a regular occurrence or seems to be a one-off.

I originally had a one-way booking for 2 persons + infant from LHR to DXB in J. Cost of 50.4k Avios + £1327
I noticed 2 seats in First became available so called up to try and upgrade, this is where the painful experience started:

• 02/07/24: Called and was told it would cost 21k Avios total to upgrade + a few hundred £s. Leapt at that price as seemed to good to be true, after being put on hold for 10 minutes was told the figures were incorrect and would actually be 160k Avios + ~£950 to upgrade. Agent was clearly wrong as that was the cost of a new booking rather than upgrade, had to go to a meeting so said I'd call back later.
• 02/07: Called later in the day, this time was quoted 33.6k Avios + ~£800 to upgrade, with the complication that they would take a payment of ~£1200 then refund £400. Agreed to go ahead, Avios were swept off account immediately and was told payment would be processed by the billing department within 72 hours.
• 05/07: Hadn't seen payment taken so called to check if any issues, was told it would take a little bit longer so to call back in 24 hours.
• 06/04: Called again, this time was told that the billing team can 3-5 working days to process payments so to call back on 09/07 if not confirmed.
• 11/07: Got fed up of calling the normal line and waiting on hold for 20-30 minutes each time, so called YouFirst. Was told that they hadn't been able to process the payment as the 3DS code is wiped from their system after 5 days. Tried to give my card details again but their system wasn't working, was told I would receive a call back in a couple of hours. Received a call at 11pm (8 hours after I'd called) which I missed as was asleep.
• 12/07: Woke up to an email from BA asking them to call me about my booking. Called YouFirst, this time was able to give my card details was told it would be processed that day.
• 14/07: As payment still not taken, called YouFirst once more, they said they would keep an eye on it and call me if there were any issues.
• 01/08: Received another email from BA asking me to call them about the booking. Called and was told they didn't know why I would receive that as there seem to be no issues, provided 3DS code once again just in case.

So a month after upgrading, probably around 6+ hours on calls to BA including hold times, large phone bills as apparently their system doesn't recognise the keypad from a UAE number so last few calls have been from my UK number while abroad, I still haven't had the booking confirmed and therefore no E-ticket.

Is this the usual experience people have when trying to upgrade, or should I submit a complaint?

I've done similar upgrades with Emirates and Qatar and never had an issue. They normally allow the upgrade to be processed on the booking page, or via live chat with at most a couple of minute call to take the card details.

If I'd known it would have been this much effort I probably would have saved the Avios and stayed in business.