Why have you locked your topic, when it was all about trying to gain information, ?
You went to great lengths to tell us how good your set upwas and waited for constructive comments, whilst admitting your debt management skills were not the best,....
why did you not wait for more help, or answer the question asked by someone ... "are you Mr Sol"?...... at that point you locked the topic?
Asking if someone has a better " your windows have been cleaned"... slip ... will not improve your debt management skills, as that is merely informing , you have done the job , and require paying.
In the first instance you have to go out and collect,.. meet your customers and explain how you work, and how you would like to be paid in the future,.. offering the steadfast crew other alternatives...
a letter or a demand is unlikely to generate good feelings between you and your customer...
you say your management skills are good... then you should know how to talk to people, and get them on side... and get the best out of them... whilst promoting yourself, and getting them to like you too.... see your customers , smile , talk to them... and when you have explained... your letters through the door will make sense to them.
Gary.