Contract termination gone bad

I called in the *** on the 07/May/ 25 to have the number ending 7208 on I*** account to be terminated at the end of contract which is 31/July/25. Instead the gentleman on the line said he will rather have me migrated down and still be able to end my contract come July. I did not receive any email for the cancellation or migration, I only received an sms confirming my quote and it looks exactly as the one I have received for termination of 4573 number. This morning I received the sms stating the 7208 number has been upgraded to 2027. I called cancellations of which they revert me to after sales and was told I have agreed even without any written contract send to my e mail, or any sms thereafter, this is in contravention of the seller buyer agreement. All I want is the reversal of this upgrade and notice of termination at the end of contract at the end of July on 7208 number. On the 7th of May I called in to terminate and not upgrade , same as with the 4573 number.