Postal delivery service in Albufeira?

We've just moved from a year in a country area near Olhao and our postal deliveries were first class and important as we were getting all our paperwork done after moving from UK.

Now we are experiencing an atrocious service in Albufeira and wonder how it is for others and what can we do about it. We moved to an oldhouse in an old part of Albufeira.  We have our number on the door and a letter box and posted letters to ourselves.  Nothing. I asked a neighbour who told me to watch out for the postal lady and I did get her the first day after she had walked past our house. She had one of my letters in a bundle in my bag and promised she'd deliver in future. The next day we got two old letters delivered by a second lady. But one we posted last week after meeting these two ladies has not yet been delivered and no more old ones.

What is going on?