How do I relinquish diamond points

Unfortunately, there is no option to rate minus otherwise I would have given -10.
Bought a trial membership and paid over £4000. We only managed to take the complimentary week. I had made enquiries about the interval as I was planning to travel but did not due to COVID.
I was reassured that the trial membership has been extended. Last year I called to make enquiries about
2 weeks in Mauritius and I was told that the resort in Mauritius was not operating at the time of the phone call. I was being given a few other options but they were all either on the red or amber list.
In the last 2 weeks after numerous failed attempts to contact CLC / Interval or being pushed from pillar to post or being given wrong numbers plus and no reply from an email sent to them, I eventually got hold of someone who told me that although my membership had been extended my interval weeks was not transferred?? and apparently, Intervals are a “completely separate body”.

When I had made the enquiries last year at no point I was told that the interval had expired.

My argument was that there was only 1 direct debit for Trial membership which included service from the intervals. it seems that there was no consideration about the fact that the contract was drawn up pre- covid.

This is blatant theft/ fraud.