Over Billed and Plan Expiry

[#1]

Hello lovely people,

I have a contract with Plusnet that expires on 04/06/2025 and I called Plusnet on 02/06/2025 to tell them that I will not sign up for a new contract due to bad services and the fact that I have been charged £37.55 for the last three months instead of £28. So the agent on the other end told me that my next bill will be charged till 13/06/2025 and it will be the sum of £62 unless I start a new contract. The agent then said that it was stated in their terms and conditions but I got upset and told him that I will involve OFCOM. They never talk about how I will be refunded the difference between £37.55 and £28, instead, he was trying to force me to buy a new contract. 

What can I do, please?

Moderator's note:
All caps title/text edited as per Forum rules.

[#2]

If no explanation of the charge difference since March then possibly raise a formal complaint.  There has been the occasional issue surrounding the annual price rise.

What products do you have, in addition to the broadband?  Telephone call plan?  Non-included call charges?

All contracts advise of the subscription fees charged after the end of the minimum term discounts.

[#3]

If your contract expires 04/06 and your bill date is the 13th, part of that charge would be calculated at the out of contract rate and part of it at the in-contract rate, so should be correct.