www.GymRatZ.co.uk presented the following explanation :
> Jono wrote:
>> Anyone able to top up an account with SMSListo?
>>
>> Have repeatedly tried & failed - their system keeps telling me to
>> authenticate my mobile number.....which I do....& then it starts all over
>> again.
>
> You may find the answer in teh following Jono (May need to copy & paste URL
> to comlete)
> http://www.prepaidgsm.net/forum/vari...ight=voipcheap
>
> Seems there is a finite limit to the amount of accounts you can set up
> without resorting to other ways of annonimity (sp)
>
> Cheers
> Pete

Thanks.

I was beginning to suspect something like that.

I managed to use a different mobile number and verified that which then
allowed me to buy credit (with a card I've used on many Betamax
variants)