I'm not up to date, but the basic principles five years ago were that:
- anyone had the right to take unpaid* time off immediately to deal with an emergency situation including making arrangements for care, i.e. phone calls, paperwork, etc. As much notice as possible should be given but, because we're talking emergency here, practically speaking this would be a phone call asap when the problem first arose.
- this right to unpaid time off did NOT cover actually giving care, or sitting by your dependant's bedside - except possibly during the initial 'emergency'. This time had to be taken as holiday, depending on the employer's holiday rules.
* "unpaid" means that your pay packet is reduced to take account of time off, and other benefits such as holiday, pension, healthcare may be reduced proportionately, i.e. you may be required to pay to make them up = double whammy
This isn't going to sound pleasant but, from an employer's viewpoint, half a day looks reasonable, a whole day not actually unreasonable, but beyond that I'd need some convincing that there were real difficulties in arranging care. Five days sounds as though you're actually giving care, which isn't what dependant's leave is for in the case of an older dependant. Even with a child, delegation of care would be expected except possibly for very young babies and in life-threatening situations.
The legislation making dependant's leave a right was introduced to stop people getting instant dismissal at the very time when they need their job the most. This is a world better than it used to be - and makes this country's employment protection laws a whole lot more generous towards employees than others. But the legislation is there to protect your job, not your pay, benefits and holiday entitlement :<)
Sorry this isn't more encouraging news, but I suggest that CAB or ACAS will be able to give you up to date information about your rights.