Invoke Solutions, Inc. won't give me any incentives after completing 2 studies (surveys) Waltham Massachusetts

I have taken 2 studies (surveys) with tis company that lasted me more than 4 hours, one was on April 17th and the other on April 27th of this year. Each survey is $35 for a total of $70. Their timeframe to reward people is 6 to 8 weeks. It has been almost 4 months since I completed these surveys and whenever I ask them about my money they keep telling me payment is delayed. 

I am afraid what they want is try to discourage me until I'll no longer ask them, but that's not going to happen. Trust me, I didn't give you 4 hours of my time for nothing.