However, since that time, it seems as if the they have gone out of their way to make my tenancy as difficult as possible when dealing with them.

I was attempting to obtain an additional parking space and had no trouble in the past, they would always provide me with the form immediately. However, this time, I was referred to come back half an hour later. When I came back, they just ignored the door because I could hear movement inside. The final, time I went around 5:15pm and he answered but replied that "this was morning work and that I should come back tomorrow morning (which would be a Saturday)".

Does anybody think this is just coincidence/being lazy on the day or they are actually trying to make my life more difficult?

Or it could be that they are childishly taking it out on you for getting them into trouble with Management. No one on the internet can figure this out for you.

What you can do, going forward, is to be very polite in your interactions with the supers. Not super nice, just polite. When they tell you to come back, take out a notebook and jot down the exact time and day they tell you. Then, if they aren't there, you have some evidence to give to Management that they aren't being very cooperative with the tenants.