There is so much rubbish talked over customer loyalty, customers are people just like the rest of us, some are loyal some are not, some couldn't sleep if they owed you money, some would let you clean their windows for month after month, and drop you like a brick when you catch up with them and they have to pay. some will ask how many cleans they owe for, some will dispute that they owe for three cleans.
Some send a cheque for six months advance cleaning, some will move out owing you three cleans.
Believe me, I have or have had all of these customers. It's no good thinking that they will all share your values, they won't. It's no good beating yourself up trying to understand customers, take what comes and move on.
If someone asks me for a price I give them a price, I'm a window cleaner and that's what I do.
I don't care who cleaned them last, or what they were charged.
Business is business.