Looking after family

They should pay for their food, make a contribution to heating, water, electricity etc. £400 for 3 of them sounds fair to me.

Is this another of those posts where someone dives in with a worrying question, then disappears without clarifying anything?

Not enough info. Clarification needed

If their only income is son's salary, then likely £400 is beyond their means. African currencies have been hard hit by covid. The conversion rate is very low. That 400 is more than many people earn in a month. It may well be half of son's salary after tax, and he has to live too.

Try negotiation. Maybe they can pay half that until son arrives.

" I would love them to give say 400 pounds a month to help with all the extra bills They refuse what do I do"

Extra bills - are you talking about food? Yes, they should be contributing.

'Refuse' - how did you ask, and how did they refuse?

Again, not enough information on the circumstances or means of each side or the basis of the refusal, or the options for Dil to become employed. Unemployed Dil may not qualify for much help by way of any state benefits, if living with a relative.
What I don't understand is why OP hasn't asked her son directly for the contribution to support his family, if he is employed and the only available source of DiLs income.
This situation has the ability to
cause long term damage to the family relationships if not resolved soon.

If they are there long term, they should be feeding themselves and contributing towards the extra utilities as the minimum.

I can't believe they wouldn’t offer to pay for food at the very least. I’m wondering how old the grandchildren are .If they are teenagers , especially boys ,they cost a lot to feed . I wouldn’t have a clue what they should pay, but the mother must know what she normally spends on food. With extra hot water and cost of running the washing machine you must be spending a lot.

OP seems to have disappeared ? !

Aiden2. Perhaps if you could forward more information as to why / won’t help towards bills etc; we’d understand the situation better!

My daughter and her husband stayed with me for eighteen months while they were househuntng. They offered to pay rent but I refused. They could easily have afforded it but I could not contemplate charging my own child to stay in what is still her home, albeit not now the main one. Instead daughter shopped for and usually cooked meals. plus the odd bottle of wine or chocolates, etc for me!

Our son and partner lived with us for 2 years whilst they saved up a deposit, we took no money from them - they had been paying over £900 a month in rent - and they saved instead. They bought a separate fridge and shopped and cooked for themselves. They are now in their own home and we were glad to give them a headstart.

If you can afford to support your family to give them a head start that is lovely. Not everyone can though.

Aiden2, I had this problem with my eldest son. He was working and earning well - yet flatly refused to make a contribution to the household budget.

'I shouldn't have to pay to live in my home, my friends don't!' he said.

I wrote it all down (all the bills) totalled - then divided equally between the five wage earners. Still, he refused.

Under pressure from his younger (bill paying) siblings, I invited the police to have a little word with him. They pointed out that he was an adult and I had every right to throw him out. Then he agreed!

The more you give,the more they will let you,STAND your ground.
Nothing comes for free,and i agree with other posters,the conversation should have happened before they moved in.
Hindsight is a great thing.