GLG Client Operations Manager interview questions

After speaking with 5 people in the company, including HR and the hiring manager, I had a good overall impression of GLG and was very excited about the job. After the final interview - a couple of weeks before Christmas - everything went quiet. I emailed HR recruiter to ask for an update and finally got one around a week later confirming that I was the only one left in the process and would I accept an offer of X amount. I confirmed I would be delighted to receive an offer but the amount was potentially not quite enough and would it be possible to get the amount agreed on in my first interview? He stated it would be an admin issue but shouldn't be an issue and he would get back to be after Christmas as he would need approvals. At this point I felt fairly confident that I had got the job and it was merely some admin to be cleared up before the official written offer. 2 weeks after Christmas and after numerous chaser emails I am told by the HR recruiter that they can only offer me the original amount, I stated that I would be ok with that and he said he would need to check with the hiring manager. Another 2 weeks goes past and after a few chasers he gets back to me to say that they have done some benchmarking and actually they can only offer £10,000 less than the original amount we had been discussing and so apologies but they wouldn't be offering me the role. I said, I would accept less, it is not ideal but I'm not moving for the money. Again, he had to go back to the hiring manager - at this point I was getting some red flags, I still had not been given an official offer and still cannot understand why they had done a benchmarking exercise after conducting all of the interviews or why they wouldn't just decide on an amount of money and put the offer to me and let me decide whether to take it or not. I then received a call 2 days later saying I wouldn't be offered the role with the only feedback provided that I had a lack of passion, which is the first I am hearing of it, I had no negative feedback at all throughout the whole process, the only discussion towards the end was around salary. This whole thing was a complete waste of time, they treat people appallingly, avoid this company at all costs.