Welcome to the Pure Planet community. You are talking mainly to Pure Planet customers, many of whom are happy to do what they can to help.
I'm hoping that these three links may help
See what you think. My guess is you have three options
A. Wait a few more days and see if you get news of your switch
B. Download the app and start the switch there - but you won't get the £25 from moneysavingexpert
C. Contact Pure Planet - they can't respond until Monday earliest now of course. Download the app, click on the three little bars top right hand corner, select Help, choose Wattbot, put 'message the team' (without the quote marks!) in the question box then explain the situation. They promise to get back to you within one or two working days.
Best of luck! Post back here if you need more help