All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger. We ask Allaah to exalt his mention as well as that of his family and all his companions.
The scholars differed in opinion on the ruling of a travelling person if he intends to reside in one country more than four days, whether he should shorten his prayers or not.
You may refer to Fatwa 82426 where we mentioned the different views of the scholars in this issue and their evidence. We consider the view of the Maaliki and Shaafi'ee schools to be the most preponderant opinion, which states that if a traveller decides to reside more than four days excluding the day he arrives to the other country and the day he travels out of it, that he should perform the prayers in full without shortening them, whether it is in his own country or another country. For more benefit, please refer to Fatwa 84974.
As regards what you did before, which is that you combined the prayers and shortened them, it is the view of some scholars as in the previous Fatwa. We hope that there is no harm on you in what you have done and you are not obliged to make up for those prayers. According to the view that it is permissible a traveller to shorten the prayers such as in your case, then it is also permissible to combine them as per Fatwa 83821 and 90615.
Allaah Knows best.