"There was only one gate going in and it made it a long wait," Thompson said.
She said the crowd outside spilled on to the road, because of its sheer size, causing them to be "yelled at" by security.
And once in, she said, apart from the music, things were not much better, particularly as patrons needed an AWOP card, purchased on-site, to buy food and drink.
"I just thought it was a rort because you are a captive audience and you really have no choice to go and buy alcohol.
"The people who I was with have all got money on their card and they have to go online now to get their money back."
The quality of the sound was also another point of contention, with complaints about the "patchiness" throughout the venue.
She was among a number of others who took to social media to share their frustration.
Upon arriving at 4.30pm, Tracy Jones promptly went back home and came back two hours later, to a queue that was still "very long".
"We missed a lot of the concert. I've never experienced queues like that before at a Church Road event.
"I just think they didn't have enough staff to get people through the gate.
"The concert itself was fantastic. It was just the crowd management that was really the huge problem."
However, others found no problem with the gig. One woman wrote in response to people's concerns on social media: "Sorry about your bad experience. But I was there too and I never went through what you are talking about."
Neptune Entertainment director Toby Burrows said overall the event was a "resounding success".
"It was our first time at Church Road and it was great to see the venue in full swing. The artists were very pleased with the crowd and they loved the city, the venue and the atmosphere. They all want to come back," Burrows said.
As for the long queues, Burrows said the opening time had originally been 3pm, but they had communicated through their website and social media leading up to the event about the new time of 4pm.
"This was clearly our fault and resulted in a large queue gathering up to one and a half hours before we opened, creating a backlog. We managed to have over 95 per cent of the crowd in prior to the first act, however.
"We will be adding more processing lanes for future shows. Also ... almost everyone brings some type of bag or chilly bin that needs to be searched which also slows down the processing."
Regarding AWOP, he said most events were switching to a cashless system and from an event-operating perspective it was ideal.
Burrows said the lines were "very short" whenever he checked on them.
"There can be some resistance to new technology but globally this is the future for events and we have been using cashless systems at our events for around 15 years now."
