Selling customer goods while still paying them still valid. the contract isor while

I don't like how this staff operates I have 2 items with them and they always remind me of the date when the expiry date is closer, now all of a sudden they didn't and mixed up the dates I paid for the extension of the TV Skyworth all of a sudden they say my TV is expired and my documents don't say that I was looking for the date of Soni mini hi Fi radio date for extended payment. To me it seems they are ****ming me. And I called them for clarification till these day I never got respond from them, I need my radio, they think I'm a stupid I got all the documents with what they told me is not on my documents, it says a lot what they are doing to their customers.