Switch from Data Only to Data + Calls

HELP - Old data only SIM stopping me moving main phone to Smarty

I have an old data only SIM I use to use in a mobile Router, which is currently does not have an active payment. I would like to switch my main phone to Smarty, but cannot fine a way to do it.  The problems are:

1. With my old sim, I cannot select a data + calls option to renew the SIM and put it in my phone, this would be the simplest solution. I don't need this data only SIM anymore once I have switch my main phone to Smarty.
2. I have a spare new SIM, but cannot add it to my  account, yes there is the 'group' option, but I need to remove the old data SIM  from my account as I don't need it any more, and so it would not be a group.
3. No way I can delete the account associated with the old SIM and start again with the new SIM.

Does anyone have any suggestions on how to get my main phone on to smarty ?

Thanks