And some of you wonder why the window cleaning industry isn't treated as professional.
If you (or I) agree to a contract and fail to honour it, we are usually penalised in some way. Maybe we have to keep paying until the contract would have lapsed or if we pay a credit card bill late, we must pay a £12 penalty plus some extra interest.
With window cleaning, that's not so easy to enforce so we have to do it by other means - like charging more per clean if a customer wants to re-start in spring, or maybe just find a higher paid job instead. Most of us don't have a customer's signature on a contract, but it's still a verbal contract. I/we clean your windows approximately every x weeks (except for unavoidable circumstances like freeze-ups/sickness) and you pay me/us £x. If a customer says at the outset that they wish to cancel November-March cleans, I can thank them for their enquiry and decline, or I can factor that into the price. If they make that decision after the contract starts, they have broken the contract. That gives me the right to do likewise.
No emotion. No hissy fits. No Gold-style flounces.
Just a business decision.