Cannot Buy this episode

Hello, I just beat the Colorado mission after taking a break from the game for a while. I want to play the last episode but I cannot purchase it by itself. This is frustrating because I have already bought the first five episodes. I really do not want to pay $60 for just one episode when I already spent $50 on the first five. Is there anything I can do or am I SOL? I’ve read that they stopped doing it by episodes because too many people complained but for me personally buying them by the episode was perfect. I don’t understand why people were so upset by paying for each episode because it’s technically cheaper to do that even though its only by $0.06. I guess I could wait for the game to go on sale but even then, I’ll still be paying more than I’d like. Hope to hear from someone soon. Thank you.