Grandparents rights

So my sons grand pa on his other side of the family are very supportive nd love my son but i feel like they overstep some boundaries i respect they want to be apart of his life and stuff but i wake up to good morning txt from him and wyd txt throughout the day and random phone calls , and they tell me to tell my son to call him (hes only two) and im getting annoyed . his grandpa has a wife nd they even threatened me with court because i told them they can talk to him every single day im a single mom i work nd have other things to do . This been going on for awhile if i dont respond i end up getting a couple messages later that day. Am i overreacting?