it is simply made Simple Mobile, not complicated, just Simple. 
 
Please use the folling formats for types of Payments:
 
Single Line
Choose Plan > Type in This format "XXX-XXX-XXXX"
 
2 or more Multi-line Plan
Choose Plan > Type in the following format:
XXX-XXX-XXXX - 1st
XXX-XXX-XXXX - 2nd
 
Paying more than 1 individual line with the same rate plan.
Choose Plan > Type in the following format:
XXX-XXX-XXXX - 1
XXX-XXX-XXXX - 2
etc..
Then > Choose the quantity for the # of plans you are paying > 1, 2, etc...