Cashback issues.

dekaspace1

3 different sims, 2 networks, 2 different firms.

Because of the current world I got confused over cashback dates so I phoned multiple times for each to confirm, I get told X date, so I apply, I get told its too early, and its the next bill, I put the next bill in and told its the bill I previously did, so I add that one and get told its the wrong one, repeat, because of this on 1 sim I so far have missed 2 cashbacks, and 1 each on the other 2,

The staff always disagree with each other about the due dates

I put in a complaint for the one I missed 2 and never heard back.

Basically I have lost like £100 out of this due to the misinformation, I understand the staff are working from home but their mistakes have cost me this amount.

Is there anything I can do?