Can I exchange the PS4 controller?

I bought this controller from Saturn but it has been drifting for 2 months

At first it was only a little and I didn't feel like exchanging it, but suddenly the right stick just drifts upwards

I don't feel like having a repair like this, I want my money back or an exchange right away

Is that possible?

Well, you can demand it, but legally they have the right to rectification. Whether they have it exchanged (probably) or repaired, that's up to them.

At first it was only a little and I didn't feel like exchanging it, but suddenly the right stick just drifts upwards

Then it is your fault if you do not complain. Go there and then the part will be sent in. Exchange or money back is no longer possible after two months.

It doesn't matter. Even after a day the situation would have been identical.