Teamviewer 9

I bought the version 9 for life promised by Teamviewer with payment of $ 900.00 and I am retired earning this amount per month. I can not buy a new version per year from Teamviewer. Believe it was a 'VITALICIA' version and here in Brazil that word means that it lasts a lifetime without expiring the deadline. It turns out that I use to meet some customers / customers old men who have difficulties receiving emails from results of clinical tests for example I come into their machines and I help them print the results to take to their doctors.This is my job basically.It happens that now, when I try to enter, Teamviewer tells me that they have a more current version of Teamviewer When I do this, of course I install it for the free version, but the system informs me that I am using it commercially and that the session will be closed in two minutes and the connection will not complete and it will fall. should I install a version 9 on the machine of each client and block the updates? Or, in the last case, use other remote access services from other competitors such as **Third Party Product**? Have I lost my money? I can assure you that since I bought Teamviewer 9 in 2014 until today, I did not even earn half the amount invested of R $ 900.00, considering that sometimes I charge a R $ 50.00 reais but most of the time I help them and I give up without charging anything because I can not treat them as clients but as relatives or great friends and it would be unpleasant to charge money for a favor of ultility mainly concerning their health in old age. I am waiting for a help from the Teanviewer team, who always sends me emails to buy the new versions. I have more than 200 emails from all those years offering new products, but I can not afford all this and I have to use this version 9 in the best possible way, like other software I have bought for years and still use other companies.