[mothered]

I think I have a slightly larger problem on my hands now .... 😬:

“The decision was made solely by Amazon.co.uk and you must address your concerns with Amazon.co.uk.

Amazon.co.uk found that the rate at which refunds were occurring on your account was extraordinary and could not continue. 

While this activity is not directly related to your Amazon.com account, we cannot allow you to remain an Amazon.com customer when a partner site has taken this action.”

I wish you took your account history Into serious consideration before hitting the SE.

As previously mentioned, It's responsible for the Issues that continue to develop.

Not sure how Amazon.com got involved

Amazon Is not region-specific, hence they have the capacity and power to look Into external claims.

but apparently I’ve been making too many returns. I made 2 (legit) returns on cheap items (£7, £15) in September, and the iPhone a few weeks ago, but that’s it in the last 6 months.

Be sure to ask for clarification.

Amazon's assessment Is contradictory. First they've stated the Issue was with the phone Itself, and now they're claiming It's account-related due to too many refunds. Their evaluation of your claim Is a mess.

I’m not really sure what to do in this situation. Should I still press onwards with the SE? Or just cut my losses and move on for now?

Request your claim be escalated to a higher level and as said above, ask them to clarify your account history.