If you search hotels in wego.com, and go to booking.com by the link under the outcomes. You will be able to view a error rate of the hotel and may use it to do the brg. For example, the room rate is 100USD, plus 10% tax, the total would be 110USD in IHG. But for booking.com, you will find the same total rate of 110USD, but the tax is showed as 11USD, so the room rate itself is only 99.

I got numerous of successful claim through submitting the web form.

It is what I put in the column of comments in the web form of IHG.

search the date and hotel in wego.com and go to booking.com through the link under the result. select one for the room type and submit, you will find the rate i mention.
If you are not able to view the rate. Please kindly go by a mobile device or simply to the mobiles sites. Tks.