Cancelling 30 day sim

[#1]

I put in a request for my PAC number and then received an email saying plusnet were sorry that i was thinking of leaving and to ring 500 if i wanted to discuss changing data allowances.

Does this mean that once I port my number you accept I have cancelled?

I will also be cancelling my direct debit.

[#2]

Yes, that's what a PAC is for.
I wouldn't be too hasty in cancelling your DD in case you either owe or owed a pro-rata payment.

[#3]

As indicated by dvorak, no requirement to phone. If you have the PAC from P/net then just give that to the new provider. They will do the rest, e.g. port your number to them. Once the number has ported then your P/net will be cancelled automatically.

Also, as advised, do not cancel the P/net DD until any monies owed to them or due to you has been finalised and your new provider is up and running.