Direct debit sort of???

All can anyone provide some advice please? I pay for my TV paper to be delivered by quarterly direct debit. For this I am supposed to receive 13 issues. This time I have only received 11 and as this wasn't the first time this has happened have no cancelled and go e somewhere else. When I rang they promised to send the 2 missing issues and had an email confirming when I would get my last issue. O set up my new subscription accordingly. However I still haven't got the 2 promised issues and now have to pay again to buy the papers I was supposed to have delivered. When I emailed again stating I wanted a refund for the 2 missing issues as I had a new paper coming from elsewhere they just replied saying they were just going to send the 2 issues again. It appears they didn't bother to read my email requesting the refund so now want to know what my rights are. I just want a refund for the 2 issues they failed to send and replied to that second email reitterating the first request for a refund

Any advice please?? 😀