Cancelling subscription issues

We have been a customer for a few months. Due to our new car arriving slightly later than planned we cancelled our subscription with Onto 4 days after its renewal.
Upon confirming the cancellation, we enquired about a refund as the car will have only been used 4 days out of the month that we have paid for in advance.
We were advised that any refund gets put into our Onto account. I explained that we will no longer be using the account due to having the new vehicle. I was informed that they can only refund the Onto account and if that is not used within a year then the refund expires and is void.
Obviously we were not happy with this as it is a lot of money to pay for something we no longer have.
We asked for a call back from a supervisor. This call was made on a Sunday, unfortunately, we were unable to answer the phone. An email was then sent to us from escalations with the following:

“Unfortunately, as the subscription is paid for upfront and used towards the subscription and insurance costs, we do not refund for any unused time. As the subscription is a monthly rolling contract, we charge you for a month at a time and the subscription fee is non-refundable once the subscription month has started. I do apologise for any inconvenience this causes you”

This is already different from what we were advised about it being refunded to the Onto account.
I cannot understand how it can be justified to invoice the full monthly amount for an item that is not being used. Surely there should be a part refund with a cancellation fee, rather than just taking the whole amount.
It would be very interesting to have a breakdown of the costs that Onto will incur for those 4 days that we have gone into the renewal.
Any replies will be appreciated.

Unpopular reply, but that’s their Terms and Conditions unfortunately - it’s a 30 day contract, which you’ve agreed to when you renewed for that month, even though you only wanted the car for four days.

If I cancel my 30-day mobile contract four days after it renews I wouldn’t expect a refund from that either.