While I am not familiar with Platinum Research, I expect that they function in a similar manner to the other writing companies when it comes to assigning work to new writers. That is, I am assuming that you are a newly hired writer at that company. Since you have not had any order for the past 2 months, it is quite possible that you are trying to bid on work orders that are above your pay scale. Try to aim for the lowest priced orders and see if that triggers something in the system that will allow the work to be assigned to you.
You have to start with the lowest priced orders and simple instruction orders (grade school level) at the start of your relationship with a writing company. Once you have proven your reliability with the small orders, the QA department should become more confident in allowing you receive the second tier orders and so on and so forth.