Could I please have some advice on the following seating issue?

I made a return SH flight booking when Bronze. I paid for 2 x exit row seats on the outgoing leg as they are my preference in ET. The return leg is CE and as I knew I would be Silver soon I left these.

Fast forward to a point when I am now Silver, looking at the seat plan, all options are still chargeable. My preference of available seats is 2 a/c. I called the Silver line to be told because I had booked and paid for my outgoing leg whilst Bronze, I had to pay for the return.

I queried this and after some time on hold was told as a gesture of goodwill I could have 4 a/c FOC. 2 a/c isn't available to me at all (she said it was bulkhead) At this point I thanked her and left the call.

Sooo...My query is do I pay for 2 a/c and request a refund? Or do I take 4 a/c and hope I can move to 2 a/c online.
Am I being blocked from 2 a/c because I am now Silver and the FOC seats are just the ones further back on the plane?

Any advice would be gratefully received.