How do I add a data promo code (I am a long term customer)

[Mollins]

I have been a customer with public mobile for years and I notice that the data plans they offer are really low on data compared to other companies for the same price. I see that they have a 12GB gigabyte data promo code. How do I add this as I am an existing customer.

[softech · Accepted solution]

@Mollins the promo 12GB for 12 months is for new activation only.  Not existing customers 

But there is a good deal $40 for 15GB, no expiry.   You might want to consider that