This is something I would advise against unless you are willing to go to prison, it is highly illegal and to be honest, the mobile networks well aware that this crime goes on, and I'm sure they must have a process in place to deter people from abusing their system - which may involve reporting this type of fraud to the police!
Remember you would be using a phone with GPS tracking etc. Even if it is a pay as you go sim, the network will realise and be able to find you through the phone that you are using.Today there are many plans with unlimited everything for fairly reasonable fees.
I personally get unlimited texts and data on my main sim and I have another with unlimited calls.
Unfortunately I am not sure what country you are in, so to try to advise you on the best network would be unhelpful but there are definitely low cost, legal ways to do this.