@Ef1 Sorry to hear you're thinking about cancelling. I can take you through all the information you're requesting. I'll need to check your account so can you send a PM to me with you number, full name, address and date of birth please? If you know the cost of your plan each month (leaving out any extra charges for things not included in your plan) and you know how long you have left you can calculate this yourself. I've given an example below.
The cancellation fee is made up of your monthly price plan charge and thats multiplied by the number of months left in your contract. If you are on a €60 price plan and have 3 months left then the cancellation fee will be €180 and thats added onto your bill.