go back on contract with my mobile phone

...signed up for a contract phone. I am hoping to stay within the limit this time and not go over. I’ve gotten a good deal so hopefully it will be enough to see me through each month.
I’ve also signed up for 24 months so I will at least have the same number for the next two years which will be the longest I’ve ever kept my number for. Right now the number I have I’ve had for about 20 months which is pretty long but I’ve gotten a new number with my contract so I will change even though I could have my current number switched over I fancy a change of number.

...twice. The first time I was 21 and I couldn’t keep my bills low enough. My first months bill was £350 and I could just afford to pay it and the rest were around £200 a month and it just got too much and in the end I didn’t renew the contract when the 12 months was up.
About 12 months later I decided to try again and signed up for another contract and I had smaller bills but they were anywhere from £100-200 a month and that was just way too much to pay so I cancelled that contract. I’ve not had a contract phone for around 2 years now, instead I just have a “pay as you go” phone and top up by £10 a month. £10 lasts me the full month because I get 300 free texts each month and never make any phone calls so most months I end up with £10 still on my phone when I top up again. I let it get to about £30 on my phone and then I don’t top up for a week or so to use some of my credit up.
Some weeks I top up by £20 but that’s rare.
I miss being able to make calls on my phone, because I don’t want to use my credit up, so I really want to go back on contract when I get a new phone so I am looking into some price plans over the weekend.