Switching to credit account

Been with bulb several years, in this property 3 yrs plus, credit electric account but had pre pay gas since being here due to previous Tennant not paying bills. Contacted bulb in March to ask to swap to credit for both and change to smart meters. Finally had meters switched 6th June, but still on payg for gas, Contacted bulb 2 x via chat and told in process by 1 person and we’ll check and email by other person. Now emailed to gind out and after incorrectly being told i need credit check, told the swap would be actioned today. No idea how long it will take and being charged more still for gas until it changes. Can anyone advise how long it is likely to take ?