Aarthi scans and labs - Had called and inform to come before time

I have booked appointment for my grandfather brain MRI between *-*pm time slot. After booking my appointment i had call by a female staff of their head office that you can at *pm but I decided to reach there by *pm. Once I reached and ask for appointment there, at the reception counter they told me that come after * hours your booking slot is *-*pm. Then i called to their head office they said give phone to receptionist! I given him my phone and receptionist said there is no slot till *pm his manager also said there is no vacant slot please wait. My grandfather is about ** year old and he is patient of sugar and also deases of brain stroke, he can't walk with themselves. i request to each concerned people at reception including manager but no one has respond. There is no channel for senior citizens/disable people. I got suffered approx *:** hours but they didn't start examination. This is totally unfair, their head office staff have totally fake commitments. Very worst experience.