Yes I know the message you meal gness. I'll give it a try and if that doesn't work I'll try txting the credit voucher number.
Trouble is I would have like to add it before telling the recipient . She's not very good with phones and probably wouldn't bother. I know she is very short of credit and I would like to keep in touch.
It depends on what is offered by the company self-service equipment. Sometimes if you call in on, say a landline, it may ask what phone you wish to top-up. It may be worth calling the T-Mobile IVR and see what options the menus give you.
It's also worth remembering that you can top up any mobile phone, directly from your bank account, from almost every ATM in the country. (All High Street bank cash machines offer the service).