Non-delivery of registered letter

On January 10 I found a note (Reg. No. 011901288 (MT)) from Maltapost in my letterbox saying that the postman had come with a registered letter but found no one at home. It stated that he would make another three attempts in the following three days, or I could phone on 2596 1600 and collect the letter myself.

The next day I went to the Qormi branch to collect the letter and I was told to go to another branch in Qormi (near La Rose Factory) from where I could collect it. From there they sent me to another branch in Marsa. Unfortunately I was late for work so later that day I phoned the number shown in the note to find out exactly where to pick the letter up from.

I was told to give my details and to collect it on that Monday or Tuesday until 4.30 p.m. since it was in the postman's possession on the previous days. But I then received a call from the Marsa branch telling me that the letter had already been returned to sender.

I spoke to the postman in charge and he told me that since I live in a flat he had found it difficult to find the doorbell so he could not hand me the registered letter unless he met me near my letterbox. I asked him where I should go to collect the letter and he told me to hold the line because he had to ask his senior. In the background I heard him say: "There is no one here. What should I tell him? He's on the line. Should I put the phone down?" After a while the line went dead.

I phoned the Marsa branch again and a lady spoke to me. When I told her what had happened she said there was nothing else that could be done to track down the letter and to go and collect it myself from the sender.

Is this the way Maltapost delivers registered letters? What can I do to recover the letter, which is an important one for me? What can I do in the future seeing that the postman does not deliver registered letters to my door?