It appears that during the remainder of the first month on the Rain Mobile network after Free Unlimited Data Days (FUDDs) have finished & Unlimited Off Peak (UOP) (19 hours/day) has been enabled before start of use, is the only time a Spend Limit (SL) below R250 can be set.
If no UOP has been enabled, true R0 spend limit can be set.
It is assumed the billing system allows for a minimum SL to be set before start of use, that allows for pro rata UOP to be used for the remainder of that first month of use.
Then, when the following month (first full month of billing) approaches & billing has been generated for the first payment (pro rata month billing in arrears + first full month billing in advance), it will not be possible to set a SL lower than R250 when UOP has been enabled.
Please correct where t&c's & own experience differs from this explanation.
Reason for this lengthy explanation is to help others avoid a R500 first payment even when minimal pro rata UOP was expected + first R250 in advance for first full month.
If no UOP has been enabled, true R0 spend limit can be set.
It is assumed the billing system allows for a minimum SL to be set before start of use, that allows for pro rata UOP to be used for the remainder of that first month of use.
Then, when the following month (first full month of billing) approaches & billing has been generated for the first payment (pro rata month billing in arrears + first full month billing in advance), it will not be possible to set a SL lower than R250 when UOP has been enabled.
Please correct where t&c's & own experience differs from this explanation.
Reason for this lengthy explanation is to help others avoid a R500 first payment even when minimal pro rata UOP was expected + first R250 in advance for first full month.