Internet disruptions and delays in the purchase of pre-paid electricity vouchers are causing massive queues for electricity cards around the city.
Disgruntled customers have to wait for up to two days or more in some instances just to purchase an electricity token.
The pre-paid power system was recently unveiled in the city suburbs of Kitintale, Mbuya, Bugolobi, Mutungo, Luzira, Biina and Kinawataka with the aim of going countrywide in the next six years.
"Yesterday, I was forced to wait for four hours to purchase an electricity voucher, leaving my people at home in darkness. Even then, the network did not return and I went back home at 11:00pm empty handed," said James Kalyango, a resident of Mutungo.
Umeme introduced the $3.5m (sh8.7b) system last year as one of the ways to stem power thefts and the increasing complaints of overbilling by customers.
The pre-paid meter system works on a telecom network, which makes it susceptible to intermittent disturbance whenever the network is affected.
Some clients have claimed huge business losses owing to the power blackouts from system failure to issue vouchers. Most are questioning the rationale behind launching an untested system.
Umeme says it is taking action.
Kirunda Magoola, the Umeme spokesperson, said measures were underway to introduce a smart routing system for existing electricity vendors, where if one Internet Service Provider fails or slows down, the device will automatically switch to a backup system. He added that this may take up to two weeks to resolve.
"We have also identified, through a transparent and auditable process, our first super vendor who will be fully operational by end of August," he said.
The firm is also set to open six extra outlets in the Bugolobi and Kitintale area to decongest the existing vendor outlets at Nakumatt shopping mall.
The National Water and Sewerage Corporation announced recently it was also introducing the pre-paid system.