I need a plan as cheap as possible. I have a main post paid sim card under my company with unlimited data and calls.

Now I have 2 Sim cards that i just want to maintain the validity. What plan is suitable for these sim cards? No need do make calls or have data.

My 4th Sim, I'd like to maintain validity and have a data plan of about 2gb. No need for calls. What plan would be suitable for this?