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.
First of all, you should know that it is the work contract which determines the nature of the relationship between the employee and the company, and clarifies the rights and obligations of each party; and both parties are obliged to abide by it as long as it does not contradict the religion. Allaah Says (what means): {O you who believe, fulfil your obligations.}[Quran 5:1]. Moreover, the Prophet said: "Muslims should fulfil their conditions." [Ahmad]
Therefore, if you are not obliged according to the work contract to do the different works which you mentioned, then it is your right to ask for additional payments in return for the work you are doing since it is outside your main job for which the company hired you.
Allaah Knows best.