Hello,
If you became a customer before January 27, 2015, you are on a grandfathered plan and cannot change it for another one that is grandfathered. You can transfer only to one of the new plans, which are listed on this site's home page.
If you transfer from your grandfathered plan, you will no longer have access to live customer assistance. Instead, you will have to communicate with Public Mobile by web mail only. Unlike grandfathered plans which remain at the same price year after year, new plans are not price-protected. As I tell everyone who is on a grandfathered plan, thinking of transferring to a new plan, think twice before switching because there is no going back!
If you are on a new plan at present, all that is required to change your monthly plan is to pick those options that you want, just like you did when you first became a customer. Since Public Mobile is entirely prepaid, you must first have sufficient funds in your account before a new plan can be activated.
Words of caution: If you choose a new plan, it comes into effect IMMEDIATELY, assuming that you have sufficient funds in your account prior to the change. The plan that you will be leaving will no longer be in effect. There is no partial or full refund for a plan that is left before its 30 days of service are used. For example, let's say that you paid $45 for a plan on July 1. You decide, on July 16, to buy a new plan. The new plan will become effective that day, and there will be no refund of any amount for the remaining days in the $45 plan. As a result, I recommend that, on the day before your current plan expires, buy the new one.
Whether you are on a grandfathered or new plan, I hope that I have answered your question.
Cheers.